December 2010 - OurFood-news

30.12.2010: Olive fruit fly [1]

Olive fruit fly, Bactrocera oleae (Rossi) is the major pest of commercial olive trees in the  northern, eastern and southern Africa, Southern Europe, Canary Islands, India, western Asia. The pest is known in California since 1998, originating probably from France. It developed insecticidal resistance to organophosphates. Promising parasitoids attacking olive fruit fly are Psyttalia lounsburyi, P. dacicida, P. concolor, P. ponerophaga, Utetes africanus and Bracon celer. The authors suggest further investigations on parasitoids as control agents for olive fruit fly for different climatic regions.



University of California Pest Management Guidelines [2]

Olive fruit fly larvae feed in olive fruits causing damage. There is zero tolerance for damage on table fruit and about 10% for oil olives. Sanitation is important burying all fruit that are on the ground. GF-120 Fruit Fly Bait, sprays of kaolin clay, and mass trapping are acceptable for use in an organically certified crop.



[1] Daane KM, Johnson MW: Olive fruit fly: managing an ancient pest in modern times. Annu Rev Entomol. 2010;55:151-69.

http://www.ncbi.nlm.nih.gov/pubmed/19961328



[2] How to Manage Pests. UC Pest Management Guidelines

http://www.ipm.ucdavis.edu/PMG/r583301311.html



30.12.2010: High contamination of salad leaves found in United Arab Emirates [1]

According to Dr Dennis Russell mustard salad greens, known as arugula salad leaves, or jargeer greens (Eruca sativa) were found to be highly contaminated with faecal coliform cells and Escherichia coli bacteria after washing the leaves three times. These bacteria were found even after rinsing with diluted chlorine bleach. Some strains of these bacteria can be deadly. Dr Tibor Pal stressed that high levels indicated faecal contamination and risk of other serious diseases, such as viruses and parasites.



The United Kingdom and Germany have limits of 100 E. coli bacteria per gram, and Switzerland has a limit of 10 per gram. Brazil has a limit of 100 viable faecal coliform per gram.



Jargeer greens grown on United Arab Emirates (UAE) produce farms, are a favourite and popular part of the traditional Arab meal. The authors stress that contamination occurs on the farm, if raw or poorly composted manure is used to fertilize the produce and if untreated liquid manure is used for irrigation or as a foliage spray. Contaminated jargeer are a risk of enteric disease outbreaks.



High efforts to exclude disease organisms from farms growing irrigated lettuce and leafy vegetables at California were started following a deadly outbreak of Escherichia coli O157:H7 on August 2006 regarding fresh spinach, followed by several cases of hemolytic uremic syndrome (HUS) in September 2006. Contaminated surface water and vectoring by wildlife, most likely feral pigs are the most important sources of contamination. [2]



[1] Russell DJ, Abdul Majid S, Tobias D: The presence of persistent coliform and E. coli contamination sequestered within the leaves of the popular fresh salad vegetable “Jarjeer / Rocket” (Eruca sativa L.).

http://microbiology.eajbs.eg.net/pdf/vol2.n2/1.pdf



[2] Crohn DM, Bianchib ML: Research Priorities for Coordinating Management of Food Safety and Water Quality. Journal of Environmental Quality, Vol. 37 No. 4, p. 1411-1418. Doi: 10.2134/jeq2007.0627

https://www.soils.org/publications/jeq/articles/37/4/1411





29.12.2010: Viral infections of bees are implicated in Colony Collapse Disorder[1]

Cox-Foster and colleagues 2010 found that native pollinators, like wild bees and wasps, are infected by the same viral diseases as honey bees and that these viruses are transmitted via pollen.



The scientists suspect that RNA viruses are a major contributors to Colony Collapse Disorder (CCD ). RNA viruses such as deformed wing virus, sacbrood virus and black queen cell virus were detected in pollen pellets collected by bees.



The detection of RNA viruses in other pollinators, including bumble bees, solitary bees and wasps, suggests that viruses might have a deep impact on ecosystem health.



The authors stress that pollen is currently being imported into many countries to feed honey bees used in agricultural pollination, increasing the risk of a wide spread of Colony Collapse Disorder.





[1] Singh R, Levitt AL, Rajotte EG, Holmes EC, Ostiguy N, et al. (2010) RNA Viruses in Hymenopteran Pollinators: Evidence of Inter-Taxa Virus Transmission via Pollen and Potential Impact on Non-Apis Hymenopteran Species. PLoS ONE 5(12): e14357. doi:10.1371/journal.pone.0014357

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0014357





22.12.2010: Differentiation of progenitor cells into energy-burning brown fat cells as anti-obesity therapy 22.12.2010: Differentiation of progenitor cells into energy-burning brown fat cells as anti-obesity therapy %5B1%5D According to Tim J. Schulz and colleagues 2010, brown fat cells are specialized for energy expenditure and may be included in a strategy for body weight reduction. The authors found that progenitor cells in mouse white fat tissue and skeletal muscle %28Sca-1%28+%29/CD45%28-%29/Mac1%28-%29; referred to as Sca-1%28+%29 can be transformed into brown fat cells. The authors report that fat cells, marked with Scal protein and exposed to BMP-7 protein, presented characteristics of brown fat cells. The differentiation could be intensified by adding rosiglitazone, known as a diabetes drug. The molecular characteristics of tissue-resident adipose progenitors were determined by the group around Schulz. The authors stress that diet and exercise are still the best approaches for losing weight in the general population. Therapy involving energy-burning brown fat cells may, however, help people with heavy body weight problems. %5B1%5D Schulz TJ, Huang TL, Tran TT, Zhang H, Townsend KL, Shadrach JL, Cerletti M, McDougall LE, Giorgadze N, Tchkonia T, Schrier D, Falb D, Kirkland JL, Wagers AJ, Tseng YH: Identification of inducible brown adipocyte progenitors residing in skeletal muscle and white fat. Proc Natl Acad Sci U S A. 2010 Dec 20. http://www.pnas.org/content/early/2010/12/16/1010929108">[1]
According to Tim J. Schulz and colleagues 2010, brown fat cells are specialized for energy expenditure and may be included in a strategy for body weight reduction. The authors found that progenitor cells in mouse white fat tissue and skeletal muscle (Sca-1(+)/CD45(-)/Mac1(-); referred to as Sca-1(+) can be transformed into brown fat cells. The authors report that fat cells, marked with Scal protein and exposed to BMP-7 protein, presented characteristics of brown fat cells. The differentiation could be intensified by adding rosiglitazone, known as a diabetes drug. The molecular characteristics of tissue-resident adipose progenitors were determined by the group around Schulz.



The authors stress that diet and exercise are still the best approaches for losing weight in the general population. Therapy involving energy-burning brown fat cells may, however, help people with heavy body weight problems.



[1] Schulz TJ, Huang TL, Tran TT, Zhang H, Townsend KL, Shadrach JL, Cerletti M, McDougall LE, Giorgadze N, Tchkonia T, Schrier D, Falb D, Kirkland JL, Wagers AJ, Tseng YH: Identification of inducible brown adipocyte progenitors residing in skeletal muscle and white fat. Proc Natl Acad Sci U S A. 2010 Dec 20.

22.12.2010: Differentiation of progenitor cells into energy-burning brown fat cells as anti-obesity therapy %5B1%5D According to Tim J. Schulz and colleagues 2010, brown fat cells are specialized for energy expenditure and may be included in a strategy for body weight reduction. The authors found that progenitor cells in mouse white fat tissue and skeletal muscle %28Sca-1%28+%29/CD45%28-%29/Mac1%28-%29; referred to as Sca-1%28+%29 can be transformed into brown fat cells. The authors report that fat cells, marked with Scal protein and exposed to BMP-7 protein, presented characteristics of brown fat cells. The differentiation could be intensified by adding rosiglitazone, known as a diabetes drug. The molecular characteristics of tissue-resident adipose progenitors were determined by the group around Schulz. The authors stress that diet and exercise are still the best approaches for losing weight in the general population. Therapy involving energy-burning brown fat cells may, however, help people with heavy body weight problems. %5B1%5D Schulz TJ, Huang TL, Tran TT, Zhang H, Townsend KL, Shadrach JL, Cerletti M, McDougall LE, Giorgadze N, Tchkonia T, Schrier D, Falb D, Kirkland JL, Wagers AJ, Tseng YH: Identification of inducible brown adipocyte progenitors residing in skeletal muscle and white fat. Proc Natl Acad Sci U S A. 2010 Dec 20. http://www.pnas.org/content/early/2010/12/16/1010929108 http://www.pnas.org/content/early/2010/12/16/1010929108





18.12.2010: New anti-obesity drug Contrave
A combination of the dopamine and norepinephrine reuptake antagonist bupropion and the opioid antagonist naltrexone were proposed to treat obesity. The dual mechanism of action is to stimulation of central melanocortin pathways, resulting in increased energy expenditure and reduced appetite. Contrave of Orixegen will be approved by FDA in a combination of 360 mg bupropion and 32 mg naltrexone in a single table [1]



The recommended daily dose of Contrave is two 8mg naltrexone/90 mg bupropion tablets taken twice daily (4 tablets total - 32 mg naltrexone, 450 mg bupropion). Upon initiation, the drug will be started with a quarter-dose (or one tablet) for one week and a pill will be added to the regimen each week until the full recommended dose is reached on Week 4. Treatment is designed to affect the hypothalamus to decrease food intake over extended period of time. [2]



The US Food and Drug Administration Endocrinologic and Metabolic Drugs Advisory Committee gave a positive recommendation for the use of Contrave in the treatment of obesity and weight management. The final approval is expected for Jan 31, 2011. Its use may produce a decrease in bodyweight of 5 percent. But this drug showed weight loss only when combined with lifestyle modification. The underlying causes of obesity must also be addressed such as promoting the modifications of lifestyle, diet, and exercise. [3]



Hypothalamic melanocortins, particularly α-MSH, are known to constitute the main brake to consumptive behaviour of food. Opiates are known to both suppress α-MSH and to stimulate hedonic food consumption, therefore the antagonism between melanocortins and opioids are promising to reduce obesity. Monoamines, opioids and cannabinoids are known to be involved in appetite regulation acting on the hypothalamic appetite regulatory centre, more studies on this subject are being suggested by Reece 2010. [4]



The Contrave Obesity Research I (COR-I) study assessed the effect of naltrexone and bupropion treatment on bodyweight in overweight and obese participants. The adverse event were nausea, headache, constipation, dizziness, vomiting, and dry mouth. A transient increase of around 1.5 mm Hg in mean systolic and diastolic blood pressure was followed by a reduction of around 1 mm Hg below baseline. No increase of depression or suicidality events compared with placebo were noted. [5]



Nathan and colleagues 2008 stress that antiobesity drugs target the central neurochemical systems including the monoamine, opioid, and cannabinoid systems which also modify emotional behaviour and cognitive function, acting on the receptors within the fronto-striatal and limbic circuitry. Drugs targeting the m-opioid receptors, such as naltrexone and combination therapies targeting the opioid and monoamine systems, such as Contrav were reported to produce sedfation and tiredness. The authors recommend, therefore, to assess assess neuropsychiatric adverse events antiobesity drugs with such central mechanism of action.[6]



[1] Klonoff DC, Greenway F: Drugs in the Pipeline for the Obesity Market. Journal of Diabetes Science and Technology. Volume 2, Issue 5, September 2008.

http://www.journalofdst.org/Journal/pdf/September2008/VOL-2-OBT2-KLONOFF.pdf



[2] Wikipedia: Bupropion/naltrexone

http://en.wikipedia.org/wiki/Bupropion/naltrexone



[3] New obesity pill: new hopes, old fears. Editorial. The Lancet, Volume 376, Issue 9758, Page 2042, 18 December 2010 doi:10.1016/S0140-6736(10)62281-7

http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2810%2962281-7/fulltext?elsca1=TL-171210&elsca2=email&elsca3=segment



[4] Reece AS: Hypothalamic opioid-Melanocortin appetitive balance and addictive craving. Med Hypotheses. 2010 Oct 4.

http://www.ncbi.nlm.nih.gov/pubmed/20926200



[5] Greenway FL, Fujioka K, Plodkowski RA, Mudaliar S, Guttadauria M, Erickson J, Kim DD, Dunayevich E; COR-I Study Group: Effect of naltrexone plus bupropion on weight loss in overweight and obese adults (COR-I): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial. Lancet. 2010 Aug 21;376(9741):595-605.

http://www.ncbi.nlm.nih.gov/pubmed/20673995



[6] Nathan PJ, O'Neill BV, Napolitano A, Bullmore ET: Neuropsychiatric Adverse Effects of Centrally Acting Antiobesity Drugs. CNS Neurosci Ther. 2010 Jul 7.

http://www.ncbi.nlm.nih.gov/pubmed/20626429





15.12.2010: Urinary bisphenol A linked to reduced fertility [1]

Bisphenol A (BPA) is known to be an endocrine disruptor. It found in polycarbonate bottles release which release BPA to water and other beverages. It is also found in canned foods leaching from the protective lining of cans, and many common consumer products. In animals, BPA caused oocyte aneuploidy which is an abnormal number of chromosomes, and is a type of chromosome abnormality. An extra or missing chromosome is a common cause of birth defects. BPA also reduced production of oestradiol. Mok-Lin and colleagues 2010 studied the association of urinary BPA and the reduction of number of oocytes retrieved and peak oestradiol levels.



These findings were confirmed by a study of Fujimoto and colleagues 2010 which found an inverse association between serum unconjugated BPA concentration and normal fertilization. [2]



[1] Mok-Lin E, Ehrlich S, Williams PL, Petrozza J, Wright DL, Calafat AM, Ye X, Hauser R: Urinary bisphenol A concentrations and ovarian response among women undergoing IVF. Int J Androl. 2010 Apr;33(2):385-93.

http://www.ncbi.nlm.nih.gov/pubmed/20002217



[2] Fujimoto VY, Kim D, Vom Saal FS, Lamb JD, Taylor JA, Bloom MS: Serum unconjugated bisphenol A concentrations in women may adversely influence oocyte quality during in vitro fertilization. Fertil Steril. 2010 Dec 4.

http://www.ncbi.nlm.nih.gov/pubmed/21122836




12.12.2010: Effect of storage temperature and aw on Enterobacter sakazakii in powdered infant formulas [1]

A study of the survival of Enterobacter sakazakii in milk-based and soybean-based powdered infant formulas found that the number of inoculated bacteria decreased significantly in all formulas in the aw range of 0.25 to 0.50 during storage for 1 to 6 month at 21 or 30 degrees C. The number of living bacteria was reduced at aw 0.43 to 0.50 compared to aw 0.25 to 0.30. The authors of the study, Gurtler and Beuchat 2007, concluded that death rate of Enterobacter sakazakii in powdered infant formula is directly proportional to the rise of the storage temperature and aw. No difference was found between milk-based and soy-based formulas.



High incidence of Chronobacter spp in powdered infant formula production environment [2]

A study at a processing plant for powdered infant formula, during 2005 and 2006, found 40% of the processing environment. (vacuum cleaners and filtering (sieving) machines, fluids from the drains and swabs from contact surfaces) were found positiv for Cronobacter spp. Reich and colleagues 2010 stress the importance of monitoring of the processing environment to insure high safety and hygiene of powdered infant formulas.



Powdered infant formula milk as source of Enterobacteriaceae [3]

Oonaka and colleagues 21010 examining powdered infant formula milk found 24.2% of the samples positive for Enterobacteriaceae, and 6.6% of samples contained Enterobacter sakazakii. Enterobacter sakazakii was highly sensitive to a series of tested antibiotics.



Cronobacter resistance to dessication [4]

Cronobacter sakazakii, also known under the older denomination of 'Enterobacter sakazakii' is found in powdered infant formula and other powdered foods.. The bacteria developed resistance to desiccation and osmotic stresses, surviving more than two years in the desiccated state. When dried foods are reconstituted, it grows rapidly, becoming a risk to immunocompromised infants. Critical food production should improved control measures focusing on Cronobacter sakazakii.



Bacillus cerreus found in composite foods like pizza and raw meat, but not in milk powder [5]

Bacillus cereus may cause mild disease with short duration of symptoms. Bacillus cereus was detected in uncooked pizza bases, cooked pizzas, cooked meat pies, cooked sausage rolls, processed meats, and raw diced chicken. All samples of skim milk powder were negative for Bacillus cereus. Eglezos and colleagues 2010 suggest that spores of Bacillus cereus may have been introduced at the final product by numerous ingredients.



Bacillus cereus in dehydrated potato [6]

Dehydrated potato were found positive for Bacillus cereus in 10 to 40% of examined samples. B. cereus spores are able to survive drying of the raw vegetable and may germinate in the rehydrated mashed potato product at temperatures above 10 degrees C and below 60 degrees C to levels exceeding 10(4) CFU g(-1) which were responsible for foodborne diseases caused by rehydrated potato flakes.



Clostridium botulinum present in powdered infant formula in UK [7]

A case of infant botulismus in UK was found to be caused by spores of Clostridium botulinum from powdered infant formula. In USA 78% in market-purchased samples of powdered infant formula were found by Barash, Hsia and Arnon 2010 to contain clostridial spores. Clostridium sporogenes was the most often found, followed by Clostridium butyricum. More10 other soil-dwelling clostridial species were identified, but no neurotoxigenic bacteria were found. These findings suggest that neurotoxigenic clostridial spores, however, may also be present in powdered infant formula of the US market, write the authors.



Preparation guidelines for manufacturers of dried infant formulas [8]

Chen and colleagues 2009 verified safe guidelines for manufacturers and consumers to prepare, handle and store dry infant formula in particular to reduce the Cronobacter spp.risk.



Contaminated milk powder and dried infant formula are linked to meningitis, necrotizing enterocolitis and bacteremia in premature babies. To reduce this risk of contamination with Cronobacter spp., the authors recommend to keep larger volumes of reconstituted dried infant formula at >70 degrees C and minimize storage time. Unused reconstituted formula should be stored at <4 degrees C.



Advices and guidelines on Cronobacter spp. (Enterobacter sakazakii) [9]

Canada asked for a revision of the Code of Practice for Powdered Formulae for Infants and Young Children at the Codex Alimentarius Committee of Food Hygiene [10], following contamination incidences with powdered infant formulae Cronobacter spp (Enterobacter sakazakii) in 2003.

Canada developed Good Manufacturing Practices (GMPs) for Infant Formula in Canada. [11]

The FDA Title 21: Food and Drugs: Current Good Manufacturing Practive in Manufacturing, Packing, or Holding Human Food contains GMPs for food production in general. [12]



Codex Alimentarius: Code of Hygienic Practice for Powdered Formulae for Infants and Young Children [10]

This Code of Practice focuses on the microbiological hazards, and specifically on Salmonella and E. sakazakii (Cronobacter species). It is a combination of control measures should effectively control the identified microbial hazards in Powdered Formulas (PF).



Outbreaks of E. sakazakii (Cronobacter species) infections have led to the link with PF, especially in the context of neonatal intensive care setting. E. sakazakii (Cronobacter species) is known to be present at low concentration in a proportion of powdered formulas.



For infants at greatest risk, e.g. neonatal intensive care settings, commercially sterile liquid infant formula should be used if available unless the attending physician recommends otherwise. If a non commercially sterile feeding option is chosen, an effective point-of-use decontamination procedure should be used.



There are four routes by which E. sakazakii(Cronobacter species) and Salmonella can enter PF: 1) through the ingredients added in dry mixing operations during the manufacturing of PF, 2) through contamination of the formula from the processing environment in the steps during or following the drying, 3) through contamination of the PF after the package is opened, and 4) through contamination during or after reconstitution by the caregiver prior to feeding. E. sakazakii(Cronobacter species) may be found in many environments such as food factories, hospitals, institutions, day-care facilities and homes.



In manufacturing, the organism may gain access to the processing line and product, since current technology cannot completely eliminate this organism from the manufacturing environment.



Good Manufacturing Practices (GMPs) for Infant Formula in Canada 2006 [11]

These Good Manufacturing Practices (GMPs) establish general requirements for effective control of ingredients, formulations, processes, facilities and equipment used for production of infant formula products.



Formal HACCP and ISO 9000 programs are not mandatory for infant formula establishments at this time unless required by regulation. However, all infant formula fabricators and manufacturers are required to have in place effective GMPs and related quality control procedures which provide equivalent results, and which satisfy all applicable regulatory requirements. This GMP standard encourages the application of HACCP and ISO 9000 principles and programs in infant formula establishments as a means to identify and control critical control points, to prevent contamination and failure incidents, and to continuously improve products and processes.



Shelf life of dried onion slices [13]

Asefi and Mosaffari studied preservation methods of fried red Azershahr variety onion chopped up in 2mm slices. Frying was conducted at 150 degrees C, followed by drying to a humidity of 3-4% using hot-air dryer at 70 degrees C, and microwave, packed in aluminium foil under nitrogen gas, sealed and stored at room temperature and at -18 degrees C.



The authors report high bacterial counts after 6 month and sensory properties and vitamin C content decreased according to the bacterial count. The best sample was oven-dried, packed in aluminium foil under inert gas, and kept in a freezer up to 6 month.



[1] Gurtler JB, Beuchat LR: Survival of Enterobacter sakazakii in powdered infant formula as affected by composition, water activity, and temperature. J Food Prot. 2007 Jul;70(7):1579-86.

http://www.ncbi.nlm.nih.gov/pubmed/17685328



[2] Reich F, König R, von Wiese W, Klein G: Prevalence of Cronobacter spp. in a powdered infant formula processing environment. Int J Food Microbiol. 2010 Jun 15;140(2-3):214-7. Epub 2010 Mar 27.

http://www.ncbi.nlm.nih.gov/pubmed/20409601



[3] Oonaka K, Furuhata K, Hara M, Fukuyama M: Powder infant formula milk contaminated with Enterobacter sakazakii. Jpn J Infect Dis. 2010 Mar;63(2):103-7.

http://www.nih.go.jp/JJID/63/103.pdf



[4] Osaili T, Forsythe S: Desiccation resistance and persistence of Cronobacter species in infant formula. Int J Food Microbiol. 2009 Dec 31;136(2):214-20.

http://www.ncbi.nlm.nih.gov/pubmed/19720413



[5] Eglezos S, Huang B, Dykes GA, Fegan N: The prevalence and concentration of Bacillus cereus in retail food products in Brisbane, Australia. Foodborne Pathog Dis. 2010 Jul;7(7):867-70.

http://www.ncbi.nlm.nih.gov/pubmed/20230270



[6] King NJ, Whyte R, Hudson JA: Presence and significance of Bacillus cereus in dehydrated potato products. J Food Prot. 2007 Feb;70(2):514-20.

http://www.ncbi.nlm.nih.gov/pubmed/17340893



[7] Barash JR, Hsia JK, Arnon SS: Presence of soil-dwelling clostridia in commercial powdered infant formulas. USA. J Pediatr. 2010 Mar;156(3):402-8.

http://www.ncbi.nlm.nih.gov/pubmed/20004414



[8] Chen PC, Zahoor T, Oh SW, Kang DH: Effect of heat treatment on Cronobacter spp. in reconstituted, dried infant formula: preparation guidelines for manufacturers. Lett Appl Microbiol. 2009 Dec;49(6):730-7.

http://www.ncbi.nlm.nih.gov/pubmed/19818006



[9] Pagotto FJ, Farber JM: Cronobacter spp. (Enterobacter sakazakii): advice, policy and research in Canada. Int J Food Microbiol. 2009 Dec 31;136(2):238-45.

http://www.ncbi.nlm.nih.gov/pubmed/19487040



[10] Code of Hygienic Practice for Powdered Formulae for Infants and Young Children. Codex Alimantarius CAC/RCP 66

http://www.codexalimentarius.net/download/standards/11026/CXP_066e.pdf



[11] Good Manufacturing Practices (GMPs) for Infant Formula in Canada. 2006.

http://www.hc-sc.gc.ca/fn-an/legislation/codes/infant_formula_gmp-eng.php



[12] FDA: Electronic Code of Federal Regfulations: Title 21: Food and Drugs:

Current Good Manufacturing Practive in Manufacturing, Packing, or Holding Human Food.

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?cfrpart=110



[13] Asefi N, Mozaffari M: Effects of drying, packaging, and temperature on the quality of fried onion slices. J Food Sci. 2010 Jun;75(5):S251-4.

http://www.ncbi.nlm.nih.gov/pubmed/20629896





09.12.2010: Dehydrated Foods [1]

Drying is a method of food preservation that works by removing water from the food, which inhibits the growth of microorganisms and hinders quality decay. Drying food using sun and wind to prevent spoilage has been practised since ancient times. Water is usually removed by evaporation (air drying, sun drying, smoking or wind drying) but, in the case of freeze-drying.



Grain drying: Cereals are often dried to 14% w/w, while oilseeds, to 12.5% (soybeans), 8% (sunflower) and 9% (peanuts). Drying is carried out as a requisite for safe storage, in order to inhibit microbial growth. However, low temperatures in storage are also highly recommended to avoid degradative reactions and, especially, the growth of insects and mites. A good maximum storage temperature is about 18°C.

Spray drying is used for milk powders, freeze-drying for instant coffee, solar drying in combination with salting is ideal for dried fish, [2]



Osmotic dehydration of fruits an vegetables [3]

Maftoonazad 2010 describes the technology of osmotic dehydration used as a preparation step to further processing of foods. The foods are immersed in osmotic solutions, resulting in partial drying. During or after osmotic treatment microwave heating, vacuum, high pressure, pulsed electric field are used to to improve dehydration. Mild temperatures are employed. The moisture is removed by a liquid diffusion process, and phase change occurring in the other drying processes are avoided, resulting in improved quality of the final product.



High Pressure and pulsed electric fields as non-thermal processing of fruit and vegetable [4]

Nonthermal processing of fruit and vegetable has been revealed as a useful tool to extend their shelf-life and quality as well as to preserve their nutritional and functional characteristics. Sánchez-Moreno and colleagues 2009 describe the development on the last ten years leading to appropriate processing parameters for a safe use of these technologies.

Knorr and colleagues 2002 stress that hydrostatic pressure, electric fields, ultrasonics, supercritical CO2, in combination with conventional processes may result in improved food preservation methods. [5]



Non-thermal processes such as high-intensity pulsed electric field (HIPEF) treatments may be applied to pasteurize plant-based liquid foods to preserve and extend their shelf-life and retain minor bioactive compounds. Elez-Martínez and colleagues 2009 discuss the effects of HIPEF treatments on components of the Mediterranean diet. [6]



Freeze- drying of fish cubes [7]

Crapo and colleagues 2010 report the production of freeze-dried cubes of three species of Pacific salmon. Moisture content was less than10% and a(w) below 0.4. Freeze-drying time of 9 h resulted in cubes which may be used for ready-to-eat soups, as snack food, salad topping, and baby finger-food.



Improving freeze-drying [8]

Nail and colleagues 2002, analysing frozen systems, recommend to keep the formulation as simple as possible and reduce the content of buffer and salt to a minimum. Proteins may be stabilised by an amorphous excipient, such as a disaccharide, and a crystallizing excipient, such as glycine. Advices on how to improve freezer construction and heat transfer is being given, eliminating metal trays. Lower pressures have to fit the temperature at which the freeze-drying is being accomplished, best vapour exchange take place avoiding filling of the container about more than half of its volume.



Analytical methodology for characterization of frozen systems and freeze-dried solids should be developed, and the temperature dependence of glass transition-associated mobility, particularly at temperatures below the glass transition should be looked on. Controlling the degree of supercooling during freezing could improve product quality.



Hot-air drying and microwave-vacuum is the best dehydration method to retain polyphenols in raspberries [9]

Mejia-Meza and colleagues 2010 looked at dried raspberries prepared by freeze drying, microwave-vacuum, hot-air drying, and a combination of hot-air drying and microwave-vacuum drying methods. The authors found that ellagic acid and quercetin were present in the largest concentrations, however, antioxidant activity, compared to fresh rasperries, was reduced by dehydration. Extracts from dried raspberries by the combination of hot-air drying and microwave-vacuum drying method presented the best results of all other methods regarding the activity of the polyphenols.



Leusink and colleagues 2010 report highest retention of anthocyanins and antioxidant activity of dehydrated cranberries prepared by vacuum-microwave drying and freeze-drying than dried by hot air drying. [10]



Supplementation of nutrient media increases resistance to dehydration in yeast [11]

Supplementation in nutrient media of magnesium and calcium may improve the stability of cell membranes and dehydration stress tolerance of Saccharomyces cerevisiae, improving the production of active dry yeast preparations for food and fermentation industries.



Rappoport and colleagues 2009 suggests to incubate Saccharomyces cerevisiae culture in 0,75 M lactose solution to increase the stability of the cells during dehydration. The authors report an increase of viability and a decrease in plasma membrane permeability during rehydration, which reduces leakage from the cells.[12]



Trehalose is responsible for the survival of anhydrobiotic organisms protecting proteins and membranes from damage caused by freezing, high temperatures and dehydration. Yeasts accumulate large amounts of trehalose. [13]



Leslie and colleagues 1994 write that trehalose is needed to lower the temperature of the dry gel to liquid crystal phase transition in yeast from around 60 degrees C to about 40 degrees C. Trehalose and warm water at above 40 degrees C avoid yeast cells to pass through a phase transition during rehydration. [14]



Saccharomyces cerevisiae cells have a trehalose carrier in the plasma membrane protecting both sides of the membrane. According to de-Araujo the trehalose transport through the membranes of the yeast is performed by a system with a low-affinity uptake component and a high-affinity H(+)-trehalose symporter regulated by glucose repression.[15]



[1] Wikipedia: Drying food

http://en.wikipedia.org/wiki/Food_dehydration



[2] Deis, Ronald C: Spray-Drying. Innovative Use of an Old Process. Food Product Design 01.05.1997.

http://www.foodproductdesign.com/articles/1997/05/spray-drying-innovative-use-of-an-old-process.aspx



[3] Maftoonazad N: Use of osmotic dehydration to improve fruits and vegetables quality during processing. Recent Pat Food Nutr Agric. 2010 Nov 1;2(3):233-42.

http://www.ncbi.nlm.nih.gov/pubmed/20858191



[4] Sánchez-Moreno C, de Ancos B, Plaza L, Elez-Martínez P, Cano MP: Nutritional approaches and health-related properties of plant foods processed by high pressure and pulsed electric fields.

Crit Rev Food Sci Nutr. 2009 Jun;49(6):552-76. Proc Nutr Soc. 2002 May;61(2):311-8.

http://www.ncbi.nlm.nih.gov/pubmed/19484635



[5] Knorr D, Ade-Omowaye BI, Heinz V: Nutritional improvement of plant foods by non-thermal processing. Proc Nutr Soc. 2002 May;61(2):311-8.

http://www.ncbi.nlm.nih.gov/pubmed/12133214



[6] Elez-Martínez P, Soliva-Fortuny R, Martín-Belloso O: Impact of high-intensity pulsed electric fields on bioactive compounds in Mediterranean plant-based foods. Nat Prod Commun. 2009 May;4(5):741-6.

http://www.ncbi.nlm.nih.gov/pubmed/19445321



[7] Crapo C, Oliveira AC, Nguyen D, Bechtel PJ, Fong Q: Development of a method to produce freeze-dried cubes from 3 Pacific salmon species. J Food Sci. 2010 Jun;75(5):E269-75.

http://www.ncbi.nlm.nih.gov/pubmed/20629873



[8] Nail SL, Jiang S, Chongprasert S, Knopp SA: Fundamentals of freeze-drying. Pharm Biotechnol. 2002;14:281-360.

http://www.ncbi.nlm.nih.gov/pubmed/12189727



[9] Mejia-Meza EI, Yáñez JA, Remsberg CM, Takemoto JK, Davies NM, Rasco B, Clary C: Effect of dehydration on raspberries: polyphenol and anthocyanin retention, antioxidant capacity, and antiadipogenic activity. J Food Sci. 2010 Jan-Feb;75(1):H5-12.

http://www.ncbi.nlm.nih.gov/pubmed/20492178



[10] Leusink GJ, Kitts DD, Yaghmaee P, Durance T: Retention of antioxidant capacity of vacuum microwave dried cranberry. J Food Sci. 2010 Apr;75(3):C311-6.

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[11] Trofimova Y, Walker G, Rapoport A: Anhydrobiosis in yeast: influence of calcium and magnesium ions on yeast resistance to dehydration-rehydration: FEMS Microbiol Lett. 2010 Jul 1;308(1):55-61.

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03.12.2010: UK Soil Association calls to allows the use of sewage sludge (Biosolids) on organic land [1]

A 2010 report on phosphorus input in organic farming, released by the UK organic certification body, the Soil Association, calls on the EU Commission to allow the use of sewage sludge (Biosolids) on organic fields.



The use of biosolids in organic farming is not allowed by European regulations due to increased concentration of heavy metals originated from industrial effluent which is treated together with communal sewage. The Soil Association argues that the heavy metal levels in biosolids recently declined to a level which permits the use in organic farming. This could help to tackle the decline of phosphate mining peaking in 2033. Phosphate will then become scarce and recycling the phosphate from human excreta using biosolids may increase productivity of fields.



The report also calls to reduce meat amount in human diet, as meat production demands for higher input of phosphorus then agrarian products, this could reduce the need of phosphate rock-based fertiliser.



The Soil association stresses that organic farming relies on closed systems of fertility on the farm. Manure and compost is put back onto the land, while plants that fix nitrogen in their roots are used to build soil fertility. Agro-ecological approach to farming is opposite of more intensive approaches where large amounts of fertiliser and pesticide are added. This leaves the eco-system out of balance and deplete these resources. The report points to the fact that globally only 10% of human waste is returned to agricultural soils. Urine alone contains more than 50% of the phosphorus excreted by humans. The recycle of human excreta in organic fields,may reduce the reliance on mined phosphate.



IAASTD Report (2009) focuses on high Pesticides and chemical fertilizers agricultural runoff [2]

The report says that agricultural runoff pollutes ground and surface waters with large amounts of nitrogen and phosphorus from fertilizers, pesticides and agricultural waste. Agriculture is the main cause of pollution in US rivers and contributes to 70% of all water quality problems identified in rivers and streams.



The livestock sector has enormous impacts on the environment. It is responsible for 18% of greenhouse gases emissions measured in CO2 equivalents, and 9% of anthropogenic CO2 emissions, livestock production accounts for 70% of agricultural land and 30% of land globally



Sewage treatment and phosphorus recycling to improve water of UK rivers [3]

The Centre Européen d'Estudes de Polyphosphates cites in its newsletter municipal wastewater as an important source of phosphorus to UK rivers and the efforts to remove phosphorus from sewage, and to bringing soluble phosphorus levels down low enough to prevent eutrophication risks and meet EU Water Framework objectives (Directive 2000/60/EC [4]). Other studies found that excessive algal growth (eutrophication effects) can be effectively controlled by reducing sewage phosphorus inputs. [5]



To improve Thames water a full-scale phosphorus recovery and recycling will be installed at the Slough sewage works. The unit will recover phosphorus and ammonia from the wastewater and produce environment-friendly struvite fertiliser ((NH 4)MgPO 4·6H 2 O) which provides phosphorus, magnesium and ammonium to the plants. Struvite dissolves slowly over 6 – 9 months, thus avoiding nutrient leaching to the environment. [3]



[1] A Rock and a Hard Place. Peak Phosphorus and the threat to our food security. UK Soil Association. 2010.

http://www.soilassociation.org/Whyorganic/Climatefriendlyfoodandfarming/Resourcedepletion/tabid/1259/Default.aspx



[2] IAASTD (2009), Agriculture at the Crossroads, International

Assessment of Agricultural Knowledge, Science and Technology

for Development.

http://www.agassessment.org/reports/IAASTD/EN/Agriculture%20at%20a%20Crossroads_Global%20Report%20%28English%29.pdf


[3] Scope Newsletter 76 . Centre Européen d'Estudes de Polyphosphates. November 2010.

http://ceep-phosphates.eu/Files/Newsletter/Scope%20Newsletter%2076.pdf



[4] Directive 2000/60/EC of the European Parliament and of the Council establishing a framework for the Community action in the field of water policy

http://ec.europa.eu/environment/water/water-framework/index_en.html



[5] Jarvie HP, Neal C, Withers PJA. Sewage-effluent phosphorus: a greater risk to river eutrophication than agricultural phosphorus? Sci Total Environ 2006, 360(1–3): pages 246–53.

http://www.ncbi.nlm.nih.gov/pubmed/16226299